Method for making tubs or similar articles



June 26, 1945. R, M, CH NEY I 2,378,982

Filed Nov. 29, 1941 2 Sheets-Sheet 1 June 26, 1945. R HE$NEY 2,378,982

METHOD FOR MAKING TUBS 0R SIMILAR ARTICLES Filed Nov. 29, 1941 2 Sheets-Sheet 2 INVENTOR N fioberf/wihesney g7 Ab @07 Patented June 26, 1945 METHOD FOR MAKING TUBS on SIMILAR ARTICLES Robert M. Chesney, Alliance, Ohio, assignorto The Alliance Porcelain Products Company, Alliance, ()hio, a corporation of Ohio Application November 29, 1941, Serial No. 421,014

drawing sheet metal and, in particular, to the.

manufacture of a generally cylindrical article such as a washing machine tub or the like, by drawing and shaping fiat stock. More specifi cally, the invention concerns the manufacture of a tub for a washing machine of the skirted or jacketed type.

Washing machines having an exterior jacket or skirt spaced from the side Wall of the usual cylindrical tub have certain advantages from the standpoint of appearance and prevention of heat loss, over conventional machines having exposed tubs. It has not been possible, however, prior to my invention, to produce a tub suited for cooperation with an enclosing jacket or skirt. I have invented a novel method and apparatus for making tubs specially adapted for skirted or jacketed machines, characterized by a laterally extending, downwardly curved flange at the top of the side wall and a contracted neck therebelow, the flange being adapted to rest on a rim flange on the upper edge of the enclosing jacket or skirt. The flange on the upper edge of the side wall of the tub constitutes a continuation of the curvature of the tub cover which is usually of mushroom shape and presents therewith a streamlined appearance lacking any exposed edges or angles.

In a preferred practice of the invention, I provide a generally cylindrical blank having a latterally extending flange, by drawing fiat stock. I then subject the side wall of the blank adjacent the flange to a shaping operation, thereby producing an inwardly contracted neck joined to the remainder of the tub by a downwardly curved connecting portion. I also provided a raised shoulder above the neck. The laterally extending flange is then subjected to a die-shaping operation to impart to it a downward curvature. The extreme edge of the downwardly curved flange is then bent inwardly to form an edge bead.

The apparatus which I prefer to employ for the several steps of the method includes shaping rolls for forming the neck and shoulder and the edge bead. I utilize a segmental shaping die and a cooperating die ring for imparting to the laterally extending flange the downward'curvature necessary to provide a smooth transition from the contour of the washing machine cover to that of the-jacket or skirt.

The invention may be more fully understood from a consideration of the followingdetailed description'and explanation which refer to the accompanying drawings illustrating the. preferred embodiment and practice mentioned above. In the drawings,

Fig. 1 is a central transverse section through a tub blank as produced by the initial drawing operation, from flat stock.

Fig. 2 is a partial axial section through a pair of. cooperating shaping rolls which I utilize to form the inwardly contracted neck and the shoulder upstanding therefrom, adjacent the upper edge of the side wall of the blank.

Fig. 3 is a partial radial section through the segmental die and cooperating die ring which I utilize to impart the downward curvature tothe laterally extending flange.

Fig. 3a is a view similar to Fig.3 showing the die in its extreme downward position.

Fig. 4 is a partial plan view of the die and cooperating ring.

Fig. 5 is a partialside elevation thereof.

Fig. 6 is a view similar to Fig. 2, showing the shaping rolls for forming the edge bead on the downwardly curved flange; and I Fig. '7 is a partial side elevation, with a portion in section, showing the finished tub and parts of the cover and enclosing jacket or skirt.

Referring now in detail to the drawings, I first produce a tub blank Ill from flat stock by conventional drawing procedure. The blank I0 is generally cylindrical and includes a bottom ll,

' sidewall l2 and .a laterally extending flange I3 at the upper edge of the side wall, which lies substantially in a plane normal to the axis of the blank. After the blank H] has been drawn, the flange I3 is trimmed to-a suitable width by any convenient method or apparatus.

The blank is then subjected to a shaping operation between cooperating rolls l4 and I5 which work on the side wall adjacent the flange l3. The rolls l4 and I5 have cooperating portions l6 and I! which are curved convexly and concavely respectively. The roll l4 also has a groove I8 withwhich cooperates a bead .or rib IS on the roll IS. The roll I4 also has an ofiset 20 cooperating with asimilar offset 2| in the roll Hi.

The rolls l4 and I5 are initially spaced apart and are brought together after the blank ll! has been appropriately positioned therebetween. As the rolling of the side wall |2 of the blank adjacent the flange I3 proceeds, the rolls I4 and t5 are brought closer together until they finally reach the relative positions shown in Fig. 2'. This operation imparts an inward curvature to the portion of the side wall engaged by the curved portions I6 and ll of the rolls. This portion of the shaped blank designated 22 is concave downwardly, i. e., toward the tub bottom II and terminates in a contracted neck 23 formed by the cooperation of the groove l8 and the bead 19. At the same time, the offsets 20 and 2| of the shaping rolls produce a raised shoulder 24 upstanding from the neck 23 and spaced a short distance outwardly thereof. The flange I3 is substantially unaffected by the shaping of the side wall adjacent thereto by the coaction of the rolls I4 and |5. In other words, the shaping of the side wall is effected by deforming the latter alone. The shaping rolls, furthermore, produce a smooth surface on the downwardly curved portion 22 of the side wall, free from wrinkles or buckles, despite the fact that the neck 23 is formed by contracting the side wall from its original position. Since the upper portion of the side wall I2 is rolled between the coacting surfaces of the rolls I4 and I5, the deformed portions of the side wall have the contour of surfaces of revolution.

After shaping the portion of the side wall I2 adjacent the flange I3 as above described, I next impart to the flange a downward curvature by means of die-forming apparatus shown in Figures 3 through 6. This apparatus includes a die base 25 on which is secured a die ring 26 having a concavesurface 21 on the inner side thereof. A punch 28 cooperating with the ring 26 includes a reciprocable shoe 29 having a plurality of segmental blocks 30 pivoted thereon and provided with depending shaping portions or dies 3| conforming to the contour of the surface 2'! of the ring 26. As best shown in Figures 4 and 5, the shoe 29 has recesses 32 spaced circumferentially thereof in which hinge blocks 33 are secured. Cooperating hinge blocks 34 are secured to the segmental blocks 39 and a hinge pin 35 extends through aligned holes in the overlapping portions of the two hinge blocks. By this construction, the blocks 33 may be swung outwardly to clear the side wall I2 of the tub blank, as indicated in chain lines in Fig. 3.

To effect the shaping of the flange I3, the blank I9 is inverted and disposed with the flange on the ring 28. A centering ring 36 is vertically slidable on guide pins 3'! spaced circumferentially of the base 25 and is normally held in its upper most position by compression springs 38. As clearly shown in the drawings, the outside diameter of the ring 36 is slightly less than the inside diameter of the shoulder 24 formed in the side wall of the tub blank.

When the blank has been positioned as described, the punch shoe 29 is forced downwardly into engagement with the flange I3. It will be understood that the base 25 is preferably the platen or work table of a suitable press and that the punch shoe 29 is carried on the reciprocating head of the press. As previously explained, the blocks 30 are swung outwardly as they descend past the bottom of the blank and the side wall adjacent thereto. On engaging the flange portions 3| of the blocks and the surface 2'! of the ring 26. The centering ring 38 is forced down against the pressure of the springs 38 as the blocks descend.

When the shaping of the flange I3 as described has been completed, the punch shoe 29 is retracted. 'The blocks 30 again swing outwardly to clear the side wall of the blank. The ring 31 rises under the ressure of the springs 38 and lifts the blank from the ring 26. When the punch shoe 29 has been sufficiently retracted, the blank may be removed from the press.

At this stage, the blank has, in addition to the downwardly curved portion 22, the contracted neck 23, and the upstanding shoulder 24, an outwardly and downwardly curving flange designated 40, which is concave downwardly or toward the bottom of the tub, the same as the curved.

portion 22 of the side wall. The blank is thus ready for a final flange shaping operation which is effected by cooperating rolls 4| and 42 shown -in Fig. 6.

The roll 4| has a concave surface 43 bounded by a shoulder 44. The curvature of the portion 43 is slightly greater than that of the surface 21 of the die ring 26. The roll 4| also has an outwardly curving surface 45 between the portion 43 and the shoulder 44. The ring 42 has a groove 46 to receive the neck 23 and a rim or bead 47 to engage the shoulder 24 of the blank.

As in the case of the rolls I4 and I5, the rolls 4| and 42 are initially spaced apart sufliciently to admit the flange of the tub blank. When the blank has been positioned between the rolls they are brought together and rotation thereof serves progressively to shape the flange 4D to its final curvature and to bend inwardly the extreme edge thereof designated 48. When this operation has been completed, the blank has the appearance shown in Fig. 7, disregarding the circumferential grooves in the side walls adjacent the bottom and the stepped condition of the bottom.

I3, the blocks are swung inwardly to the position Fig. 7 clearly illustrates how the downwardly curved flange 40 constitutes a continuation of the mushroom contour of the cover 49 and provides a smooth transition between the edge thereof and the upper edge of a substantially cylindrical jacket or skirt 50. The jacket has an inturned flange 5| on which the bead 48 rests, with a gasket 52 therebetween.

It will be apparent from the foregoing description and explanation that the invention provides a simple but thoroughly practical method and apparatus for making tubs having a laterally extending downwardly curving flange adapted to harmonize with the contour of a mushroomshaped cover and provide a smooth surface joining the cylindrical jacket or skirt to the cover, thereby enhancing the appearance of the complete tub and eliminating unsightly joints. Since the bead 48 is bent sharply inward, the space between it and the skirt is barely visible. In any event this space is filled by the gasket 52 leaving a smooth exterior which can readily be cleaned. The invention provides a successful means and method for accomplishing a difflcult shaping operation without any detrimental effect on the blank such as tearing the edge or leaving buckles or wrinkles in the flange or the curved portion of the side wall. Such irregularities become quite noticeable after enameling the blank and are, therefore, seriously objectionable. The smooth surfaces resulting from the forming method and apparatus which I employ, however, may readily be enameled and when so treated exhibit a smooth surface which is entirely uniform in appearance.

The apparatus which I employ is relatively sim- I ple and inexpensive and no special skill, furthermore, is required to operate it.

Although I have illustrated and described but a preferred embodiment and practice of my invention, it will be understood that changes in the construction and procedure disclosed. may be made without departing from the spirit of the invention or the scope of the appended claim.

I claim:

In a. method of making washing-machine tubs of the jacketed type having an upwardly convex rim flange, or the like, the steps including drawing a sheet of flat stock into a cylinder having a bottom and side wall, leaving a flange around the upper edge of the side wall lying in a plane substantially normal to the axis of the cylinder, deforming said side wall adjacent said flange to produce a contracted neck on the cylinder, and

applying pressure to the flange at circumferentially spaced points on the under surface thereof within the projection of the side wall thereon, and thereby forcing the flange into a die ring adapted to impart an upwardly convex shape thereto.

ROBERT M. CHESNEY. 

